The animal that squirrels are most afraid of are domestic cats.
Cats are very effective hunters and pose a great risk and threat to squirrels.
Squirrels are also known to use very quick and evasive maneuvers as well as warning calls when they see or sense a cat around.
Squirrels are also afraid of other predators such as raccoons, foxes and hawks but squirrels fear cats the most.
Bobcats and weasels are also scary to squirrels.
Even snakes can scare off squirrels.
Squirrels have a natural fear of sudden movements and loud noises.
You can also use a motion activated sprinkler to spray the squirrel and get them to go away.
Strong odors can also deter squirrels.
Using scents such as garlic, black pepper and white pepper are also naturally unpleasant to a squirrel.
Even sweet smells such as peppermint can deter squirrels.
You can spray plants and flowers with some water and then sprinkle on some pepper or peppermint oil to deter squirrels.